import java.util.Scanner;

public class Demo06 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你的成绩：");
        int scer = sc.nextInt();
        if (scer>=0 && scer<=59){
            System.out.println("A");
        } else if (scer>=60 && scer<=80) {
            System.out.println("B");
        } else if (scer>=81 && scer<=100) {
            System.out.println("c");
        }else {
            System.out.println("输入错误！！");
        }
    }
}
